What is the emergency pill (Emergency Contraception) and how is it taken?

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What is the Emergency Pill and How to Take It

The emergency pill (emergency contraceptive pill or ECP) is a medication taken after unprotected sex to prevent pregnancy, and should be taken as soon as possible within 5 days (120 hours) of unprotected intercourse, with ulipristal acetate (ella) being the most effective oral option throughout this entire window. 1

What Emergency Contraception Is

Emergency contraception consists of methods used after sexual intercourse to prevent pregnancy 1. Common reasons for use include:

  • Contraceptive failure (such as condom breakage or missed birth control pills) 2, 3
  • Failure to use any contraception 2, 3
  • Sexual assault 1

Emergency contraception is NOT an abortion pill—it does not end an existing pregnancy. 4

Available Emergency Pill Options

There are three types of emergency contraceptive pills available 1:

1. Ulipristal Acetate (ella) - Most Effective Oral Option

  • Single 30 mg dose 1, 4
  • Effective for the full 5 days (120 hours) after unprotected sex 1, 4
  • More effective than levonorgestrel when taken 3-5 days after intercourse 1
  • Works better in obese women compared to levonorgestrel 1, 5
  • Requires a prescription 4

2. Levonorgestrel (Plan B)

  • Single 1.5 mg dose (can be taken all at once) OR two 0.75 mg doses taken 12 hours apart 1
  • Most effective within 72 hours (3 days) 1
  • Effectiveness significantly decreases after 72 hours 1, 5
  • Available over-the-counter 1

3. Combined Estrogen-Progestin Pills (Yuzpe Regimen)

  • Two doses of combined oral contraceptives taken 12 hours apart 1
  • Less effective than ulipristal acetate or levonorgestrel 1
  • More side effects (nausea and vomiting) 1
  • Only useful when dedicated emergency contraceptive products are unavailable 6

How to Take Emergency Pills

Timing is Critical

Take the emergency pill as soon as possible after unprotected sex—the sooner you take it, the more effective it is. 1, 4

  • Ulipristal acetate (ella): Take within 5 days (120 hours), maintains effectiveness throughout this period 1, 4
  • Levonorgestrel: Take within 5 days, but most effective within 72 hours 1
  • Can be taken at any time during your menstrual cycle 4
  • Can be taken with or without food 4

Important Instructions

If you vomit within 3 hours of taking the pill, contact your healthcare provider immediately—you may need another dose. 4

After taking emergency contraception, use a reliable barrier method (condoms with spermicide) every time you have sex until your next period. 4

What Happens After Taking the Emergency Pill

Expected Effects

  • Your next period may come earlier or later than expected by a few days 4
  • If your period is more than 1 week late, take a pregnancy test and contact your healthcare provider 4

When to Seek Medical Attention

Seek immediate medical care if you experience severe lower abdominal pain 3-5 weeks after taking emergency contraception, as this could indicate an ectopic (tubal) pregnancy. 4

Resuming Regular Birth Control

After Ulipristal Acetate (ella)

  • Wait 5 days before starting or resuming hormonal birth control (pills, patch, ring, injection) 4
  • Use barrier contraception (condoms) until your next period 4
  • Starting hormonal contraception too soon after ella can reduce ella's effectiveness 4

After Levonorgestrel

  • Can start or resume hormonal contraception immediately 1

Common Pitfalls to Avoid

Do NOT take emergency contraception more than once in the same menstrual cycle. 4

Emergency contraception is for emergency use only—it should not be used as regular birth control. 4

Emergency contraception does NOT protect against sexually transmitted infections (STIs) or HIV. 4

Side Effects

The most common side effects include 4:

  • Headache
  • Nausea
  • Abdominal pain
  • Menstrual pain
  • Tiredness
  • Dizziness

These side effects are generally mild and temporary 4.

Drug Interactions

Tell your healthcare provider if you take St. John's Wort or medications like rifampin, phenytoin, or carbamazepine, as these can make emergency contraception less effective. 4

Most Effective Option Overall

While this question asks about pills, it's important to know that the copper IUD inserted within 5 days of unprotected sex is the single most effective form of emergency contraception and provides ongoing contraception afterward. 1, 5

References

1
Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

3
Research

Practice Bulletin No. 152: Emergency Contraception.

Obstetrics and gynecology, 2015

5
Guideline

Emergency Contraception Options

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

6
Research

Emergency contraception: which is the best?

Minerva ginecologica, 2016

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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